1. Field of the Invention
The present invention relates to a system for the identification and automatic detection of vehicles or objects.
It can be applied notably to the detection of stolen vehicles.
2. Description of the Prior Art
A known way of coping with the shortcomings of sound alarms in vehicles consists of placing concealed electronic markers on these vehicles, so that stolen vehicles can then be identified by means of a detection infrastructure, installed at given places in a territory. A device of this type has been described, for example, in the French patent application No. 2 656 449 filed on behalf of the firm VOLBACK registered under French law.
However this approach, which is very costly, also unreliable because it calls for the setting up of a very large number of electromagnetic sensors on well-localized road circuits in a territory. This makes it necessary to guide the vehicles over the sensors and hence dissuades thieves from taking the roads on which the sensors are installed. Moreover, an informed thief can always detect the presence of a marker on the vehicle that he has stolen and then destroy or neutralize it by covering it, for example, with a metal screen that cuts off all electromagnetic radiation between the marker and the sensor. Consequently, a stolen vehicle can always move about without it being possible to detect its presence on a route where sensors are installed.